Fish Oil for Dry Eyes: What the Research Shows

Fish oil hasn't been shown to help most people with dry eye. In DREAM, a well-controlled trial funded by the National Eye Institute, 535 people with moderate to severe dry eye took either 3 grams a day of omega-3s from fish oil or an olive oil placebo for a year, and both groups improved by about the same amount. Some smaller studies did suggest a benefit, so the question of omega-3 for dry eyes isn't completely closed. In our practice, omega-3s are a case-by-case add-on to treating the cause, which for most of our dry eye patients is clogged oil glands along the eyelids. Our guide to nutrition and eye health explains where supplements fit.

Key takeaways

Research hasn't shown a dry eye benefit from fish oil for most people, and in the DREAM trial, omega-3s did no better than an olive oil placebo.
Artificial tears are the most common treatment for mild dry eye, and clogged eyelid oil glands are treated with a heated eye mask and intense pulsed light (IPL).
Ask a doctor before taking fish oil if you use a blood thinner, have the heart rhythm problem atrial fibrillation, or are allergic to fish or shellfish.
For eye health, the advice points to food: fish high in omega-3s, such as salmon, halibut and tuna, plus dark leafy greens like spinach and kale.

What did the DREAM study find?

It found that fish oil worked no better than a placebo. DREAM, short for Dry Eye Assessment and Management, ran at 27 centers and was published in the New England Journal of Medicine in 2018.

535 adults with at least six months of moderate to severe dry eye took part.
349 of them were randomly assigned to 3 grams a day of fish-derived omega-3s, taken as five capsules: 2,000 mg of EPA (eicosapentaenoic acid) and 1,000 mg of DHA (docosahexaenoic acid).
The other 186 took 5 grams a day of olive oil, about a teaspoon, in identical capsules.
Everyone was free to keep using their usual dry eye treatments, such as artificial tears and prescription anti-inflammatory drops.

After 12 months, scores on a 100-point symptom questionnaire had improved by an average of 13.9 points in the omega-3 group and 12.5 points in the placebo group. The difference between the groups was not significant, and clinic tests of the amount and quality of tears showed no difference either.

Most participants did take their capsules: blood tests at 12 months showed that 85 percent of the omega-3 group were still taking them, and their average EPA levels had quadrupled. The study's chair concluded that the results do not support omega-3 supplements for moderate to severe dry eye.

Why do some people say omega-3s help their dry eyes?

Partly because many people feel better on a placebo too. In DREAM, more than half of the people taking olive oil capsules reported substantial symptom improvement over the year, and the researchers noted how hard it is to judge whether a treatment really helps a particular dry eye patient.

Smaller studies are another reason: several suggested that omega-3 supplements might relieve dry eye symptoms. A 2022 review of 8 studies with 1,107 participants (6 testing capsules, 2 testing eye drops) concluded that supplementation may improve symptoms, though its authors noted that the studies varied in size and length and that bias was possible.

Taking omega-3s for longer didn't change DREAM's result. In an extension study, 43 participants who had been taking them were randomly assigned to continue or switch to a placebo, and after another 12 months the outcomes of the two groups didn't differ.

In a study of healthy people, they didn't prevent dry eye either: daily supplements of 460 mg EPA plus 380 mg DHA for 5.3 years did not affect the risk of getting dry eye disease.

The American Optometric Association still says supplements containing essential fatty acids may help decrease dry eye symptoms in some people, and suggests asking your doctor whether supplements could help you.

Is omega-3 good for your eyes in other ways?

As food, it belongs in an eye-healthy diet; as a supplement, it hasn't helped macular degeneration. Age-related macular degeneration (AMD) is the loss of central vision as people age. In the National Eye Institute's AREDS2 trial, adding the omega-3s DHA and EPA to an AMD vitamin formula had no additional overall effect on the risk of advanced AMD.

Is eating fish better than taking fish oil?

For eye health, the advice points to food. The National Eye Institute suggests dark, leafy greens like spinach, kale and collard greens, along with fish high in omega-3 fatty acids such as halibut, salmon and tuna. For some health conditions, the evidence for benefits from seafood is stronger than the evidence for omega-3 supplements.

EPA and DHA, the omega-3s tested in DREAM, are found in seafood, especially cold-water fish such as salmon, mackerel and tuna. A different omega-3, ALA (alpha-linolenic acid), comes from plant oils such as flaxseed, soybean and canola, and from foods like chia seeds and walnuts. Algal oils are a vegetarian source of DHA.

The National Eye Institute also says you might be more likely to have dry eye if you don't get enough omega-3 fatty acids, which are found in fish, walnuts and vegetable oils.

Is fish oil safe to take?

Side effects are usually mild, but a few people should check with a doctor first. The usual side effects are an unpleasant taste, bad breath, heartburn, nausea, stomach discomfort, diarrhea, headache and smelly sweat. Ask before you start if any of these apply to you:

You take warfarin (Coumadin) or another blood thinner. High doses of omega-3s may cause bleeding problems with these medicines.
You have atrial fibrillation (AFib), a type of arrhythmia, which is a problem with the rate or rhythm of the heartbeat, or heart or blood vessel disease. In two large trials, 4 grams a day of omega-3 supplements for several years slightly raised the risk of AFib in people with heart or blood vessel disease or at high risk of it. The label of Lovaza, a prescription omega-3 drug made from fish oils, also notes a possible link, of uncertain clinical significance, with more frequent AFib or flutter episodes in people who already have it, particularly in the first 2 to 3 months of use.
You're allergic to fish or shellfish. Fish oil supplements and Lovaza, a prescription omega-3 drug, are both made from fish oils, and Lovaza's label advises caution in people with a known allergy to fish or shellfish.

Tell your doctor and pharmacist about every supplement you take, and bring the bottles to your eye exam so the doses can be checked against your other medicines.

What can you do for dry eyes besides fish oil?

Start with the treatments the National Eye Institute lists. Artificial tears are the most common treatment for mild dry eye, and over-the-counter moisturizing gels and ointments may also help. For more serious dry eye, your eye doctor may prescribe cyclosporine (Restasis) or lifitegrast (Xiidra), eye drops that can help your eyes make more tears.

Habits help too: avoid smoke, wind and air conditioning, use a humidifier at home, take breaks from screens, wear wraparound sunglasses outside, drink plenty of water and sleep 7 to 8 hours a night.

For most of our dry eye patients, the main problem is the meibomian glands, the oil glands along the eyelids, which become clogged, inflamed or start to shut down, a condition called meibomian gland dysfunction. So treatment goes to the glands: a heated eye mask used the right way at home, and in the office, intense pulsed light (IPL) to calm inflammation and melt thickened oil, followed by gland expression while the oil is still warm.

How we approach omega-3s at Cohenmehr Optometry

Our optometrists in Los Angeles discuss omega-3s case by case, depending on your health history, and only as support alongside treatment of the glands. A dry eye evaluation starts with imaging of the meibomian glands, so we can see whether they are blocked, shortened or dropping out before we choose a treatment.

Bring every drop and supplement you use to the visit. Doses and interactions belong in your record, and we would rather take a bottle off your list than add one.

Questions patients ask

What vitamins are good for dry eyes?

Vitamin A is the vitamin the National Eye Institute links to dry eye: it says you might be more likely to have dry eye if you don't get enough vitamin A, which is found in foods like carrots, broccoli and liver. Most people in the United States get enough from the foods they eat, though, and too much preformed vitamin A, usually from supplements or certain medicines, can cause severe headache, blurred vision, nausea and dizziness. Bring any dry eye vitamin formula to your exam.

What are AREDS2 vitamins?

AREDS2 vitamins are a supplement formula from the National Eye Institute's studies of age-related macular degeneration (AMD). Commercial versions contain 500 mg vitamin C, 400 IU vitamin E, 80 mg zinc, 2 mg copper, 10 mg lutein and 2 mg zeaxanthin, and no beta-carotene. In trials, the formulas helped people with intermediate or late AMD; they cannot prevent AMD, and people with early AMD or no AMD saw no benefit. As part of macular degeneration care, we decide from your exam and imaging whether the formula fits you.

What are lutein and zeaxanthin?

Lutein and zeaxanthin are carotenoids, plant nutrients in the same family as beta-carotene that are plentiful in green leafy vegetables. In the eye they are found in the retina and lens, where they may act as natural antioxidants. AREDS2 formulas use them in place of beta-carotene, which may increase lung cancer risk among people who smoke. In the trial, people who took the formula with lutein and zeaxanthin instead of beta-carotene had an 18% lower risk of progressing to advanced AMD than those who took the version with beta-carotene.

How much fish oil is safe to take?

The FDA recommends no more than 5 grams a day of EPA and DHA combined from supplements. For comparison, the 3 grams a day tested in DREAM took five capsules. High doses of omega-3s may cause bleeding problems with warfarin (Coumadin) or other blood thinners, so ask your doctor before you take that much, and bring the bottle to your exam so we can check the dose against your other medicines.

Sources

Written by

Dr. Bijan Cohenmehr, OD

Founder of Cohenmehr Optometry, in practice for over 40 years. He leads the practice’s dry eye care and myopia management. A graduate of SUNY College of Optometry.

About Dr. Bijan →

Does Fish Oil Help Dry Eyes? What the Research Shows